Protective device for automobile-motors.



No. 835,401. PATENED NOV. 6, i906.

A. CHURGHWARD. vPROTECTIVE DEVICE FOR AUTOMOBILE MO'ORS.

APPLICATION FILED JUNBIZ, 1905.

'Hg BFTIIIJMW F UNITED STATES PATENTA OEEICE.

lALEXANDER CHURC'HWARDQ OE sCEENECTADY.NEW YORK, AssICNORTO .GENERAL ELECTRIC COMPANY. A'COEPOEATION OE NEW YORK.

- following is a specification.

PROTEoTlvE DEVICE Fon AUTOMOILE-Morons. f

rntsaafioi.

i .Appiicaion met June 12,1905. serial N0.'264,'14 =5.

Tol-*fall wlwm it may concern.l

' v Be it known that I', ALEXANDER CHURCH- wlannacitizen of thel United States', residing at "Schenectady, countyt of Schenectady,

State of New York, haveinvented certain x new and useful' Improvements in Protective Devices for vAutoinobileMotors of'which-the Th present inventionrelate's t'oc'ontrol apparatus for electric motors, and particu larly motors used for driving automobiles.

In :Patent No. 811,533, granted on'Felo-'-v .ruarjTf-, 1906, on'an applicationiiled by Anderson, there is d-iscloseda system'of. control for automobilemotors -wherein incertain running positions of .the

controller ashunt containing a resistance is placed about the 'field-windings. It is evident that if for any reason-Pastor instance, because of a bad cont acte-the circuit through the fieldwindings is opened while the shuntl ism-. position the flow of current through thestorag'e battery and armatureis limited only b f' the ohmic resist-anceoffthese ele.-

- ments #and of the shunt connection, for the motor is deprived of its field andl is therefore unable to setup an. electromotive force f .ance '.'which Awill ordinarily be connected in- 3Q.

counter to thestorage battery. The resistshunt. with the eld -windings `in vorder to raisethe speed offthe motor through weakening its eld isinsuflicient to cut down the current under such abnormal .condition to a;

value 'whereupon no injury will result to the armature or the battery, or both',

The'object--of the presentinvention is to provide means 4whereby'in the system referred to the usual ilow o f current may take place through the'motors'o long as the neld remains energized; 'but in case the iield-cir` cuit is interruptedwhile in 'parallelj with a resistance the motor-circuit will be broken.

r It'lis'well known that -when an automobile# motor is accelerating from a position of rest .or when' heavily4 loaded a '-current manyv -times greater t-han the normal current may iiow through the motor and battery for a short time. If this same current were` allowed' to How under the 'abnormal condition of Ano iield excitation, the armature and bat-- opening,v of the circuit.

tery might be irreparably injured before-the The present invention 'therefore contemplates'means which shall not' interfere wlth.

Specicatonof Letters Patent.

y contacts engages with the 'as indicated in Fig.

Patented Nov/.16, 1'906.,

the operation ofthe motor when takin a large'current when accelerating or heavily loaded, but which' will interrupt the circuit under the abnormal condition while the cur'- rent is yet comparatively small. i

The present invention'will be more vfully understood in connection with the following description thereof.

In the accompanying drawings, Figure '1 illustrates diagrammatically a control/sys-l tem embodying the present invention, and F1'gs.'2 to 5 lndicate the circuit conditions correspondingl to certain running positions of thecontroller.

f 'Reference being-had to Fig. 1,.A indicates the motor-armature, and F and F series field-windings. .B is the storage battery which supplies the motor with current. R is a resistance, `and C is acontroller.

for both forward and reverse operation; but

o only one set of running positions need here c to Wc?. A are fixed iingers be:l considered. adapted to operate with movable contacts d The controller is `arranged to connect` the motor to d for forward rotation of the motor and other contacts e to e5 for reverse operattion.

running position, wherein on set of movable Then 'the controller ismoved to the-,FS

row of fingersy along line l 1, a circuit is completed from one terminal of the battery throughthe motorarmature, through the resistance R, through contact c',l contacts d and (Z2, field-winding F, contact c, contacts d5, d3, andres, iieldt-he` 'current after it leaves the armature passes in part through section '1 of resist ance R, through contacts c7, dg, d8, (Z7, and ca, to

'In posit-ion 3 of the conthe battery, instead of passing whollyf through the field-windings after leavingfthe,v

armature. The circuit connections dent that if contact d3 should. bee

are now;

It "ie 1 come-insulated from finger c3 or ifcoil-tactjd? should. become' insulated', from contact. tty by l .reason of, dir'toroxidation or because of'llntl proper adjustments opening the ieldcircuit the battery ywill become short circuited i flow through the shunt when a portion of the total current is flowing through the fieldwindings. Should, however, the 'field-circuit beinterrupted, the entire current will iiow through the shunt, which then carries a current much in excess of tli'at intended, and the fuse f immediately blows out and inter- -u ts the entire circuit. y placing the fuse in the shunt connection instead of in the main circuit the current value' at which the circuit is interrupted un'- der abnormal conditions may be such that no serious effect is produced'upon the battery or motor-armature, while it the ruse were placed in the main cir'cuit it would have to be designed to carry a maximum current which may momentarily be used in accelerating, and the circuit would, perhaps, not be interrupted until damage had been done. Another advantage arising from placincr the fuse in the shunt-circuit is that although the motor may be inoperative in the ruiming positions of the controller wherein the shuntis employed, yet it may be operated in other positions of' the controller without replacingthe fuse, provided, ofcourse, that the defect inthe field connection is remedied or that the deect'is suc-h as not to prevent the coinple' tion ot a main circuit in some position of the controller.

In Figs. 4 and 5 are shown thc circuit connections when the controller is in its fourth and fifth running positions, respectively. The protective device, it is seen, comes into play in the final ruiming position, (shown in Fig. 5,) wherein the two field-windings instead of being in series are inr parallel and also in parallel with the resist/ance 'z'. y The particular form of motor and control/ i, system illustratedis not essential to the present invention, which inay'be employed 1n systems of various types and different -forms of series motors.

What l claim as new, and desire to secure by Letters Patent of the United States, is# 1. ln a system of control, a. motor, 'a source of current-supply, means for connecting said .motor to .said source Aof supply, means for placing a shunt about the motor eld-Winding, and means operativeunder less than n norntal `,current to 'interrupt the armaturecircuit when the held-circuit is denergized While t/hesliunt remains energized.

. 2. In a system of control, a storage battery, a motor operatively connected to said battery, a resistance connected in parallel with the motor held-winding, and means for interrupting the circuit from the battery when the circuit through t-he field is interrupted With- -out a'corresponding interruption ot the circuit through said resistance. 3. In a system of control, a storage battery,

a series motor operatively connected therewith,.a resistance connected in parallel with the 'iielchwinding of -said motoiyand means .for interrupting the circuit from the battery when the circuit including the ield-winding ruption of the circuit including said resistance, said means. being arranged to operateunder current having a value lowerv than Ausual working currents.

4. ln a system of control, a storage battery,

a series motor connected thereto, a resistanceV connected in parallel withA the field-winding of said motor, and means in the connectionI containing the resistance for interrupting the circuit from the battery upon an interruption of vthe circuit yincluding the field-winding without a corresponding interruption .of the circuit'including the resistance.

l 5. In a system of control, a storage battery, a series motor connected thereto, a resistance inparallel with the field-windingof' said inotor, vand a fuse in the connection containing the resistance, said fuse being arranged to act upon the passage oi" a current lower than usual working currents through the motorarmature.

6.1111 a system of control, a source of Vcurrent-supply, a motor, a resistance, a control- A vler arranged to connect said motor to` said source of' supply and in certain positions of the controller to shunt ,the field-winding through said resistance, and a fuse in the connection between the resistance and the controller, said fuse being arranged to actwhcn rthe current passing therethrough reaches a predetermined value which is lower than usual working currents.

In witness whereof i have hereunto set niv Yhand this 9th day of J une, l1905'.

ALEXAX DER CHRCHWARD.

XVitnesses:

BENJAMIN Ht'LL, HELEN ORFonD.

is interrupted without a correspondinginter? IOC) IIO 

